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MARCH 31, 2014

Pete Matsko, center, at his bar, Backstreet Pub and Grill in Clemson, S. C. A new concealed-weapons law in South Carolina turned his pub into a battlefield in America’s culture wars. Credit Mike Belleme for The New York Times

CLEMSON, S.C. — Pete Matsko expected a little pushback when he posted a sarcastic sign banning concealed weapons from Backstreets Pub & Grill, his beer and burger bar in this college town, but he did not expect to become a national target.

Within weeks, he was slammed with so many online attacks and harassing phone calls that he changed his number and started asking the police to open his mail.

A new concealed-weapons law in South Carolina turned his pub into a battlefield in America’s culture wars. Like an increasing number of bar and restaurant owners around the country, Mr. Matsko discovered that his politics can matter more than what he serves.

As the position restaurants hold in American culture grows, so too does the list of issues on which chefs are asked to make a stand. Refusing to bake a cake for a gay wedding, requesting that a woman not breast-feed at the table or trying to prevent a diner from wearing a gun can have serious business implications.

“It’s almost like restaurants have to have a political strategist on board now when they put together their marketing plan,” said Andrew Freeman, a San Francisco-based consultant to the restaurant and hotel industry.

Mr. Matsko behind the bar. Credit Mike Belleme for The New York Times

The shift is as much a reflection of a nation deeply divided on social issues as it is about the changing role of restaurants and chefs.

“We’ve become the national dinner table,” said David McMillan, an owner of the coastal restaurant Drunken Jack’s in Murrells Inlet, S.C., and chairman of the South Carolina Restaurant and Lodging Association.

“It’s more than just cooking food,” he said. “We have to be allergen experts and nutritional experts and now Second Amendment experts.”

Restaurants have long been social barometers, sometimes setting informal public policy by how they do business. In Northern states, a de facto set of Jim Crow laws were enforced by racially segregated restaurants. In the South, lunch-counter protests helped dismantle the region’s formal segregation laws.

Other restaurants contribute to the social debate through foundations that can sometimes bring controversy. Chick-fil-A was a target in 2012 after reports showed its foundation gave millions of dollars in donations to groups fighting gay rights.

Restaurants are no longer just places to eat, said Rich Harrill, acting director of the School of Hotel, Restaurant and Tourism Management at the University of South Carolina. They are stand-ins for the family dinner table and provide a community forum.

“It’s interesting that we started to go to Starbucks to look at the paper together and have coffee together, and now we’re having a gun discussion there,” he said, referring to a public statement last fall by Howard Schultz, the chief executive, in which he asked gun owners to not bring weapons into the company’s stores.

Still, most restaurateurs want to run a business without controversy. In states with changing gun laws, that has become a challenge.

In February, South Carolina joined a handful of mostly Southern states that allow people with permits to take concealed guns into bars and restaurants. There are two caveats: Armed patrons cannot drink alcohol, and restaurants can opt out by posting a sign banning guns.

In a state with more than 230,000 such permits and a large population that grew up with guns, the policy had strong support from many state lawmakers and both candidates in the approaching governor’s race.

Mr. Matsko, who owns two handguns, decided to post a sign in his pub banning them.

“On some nights you have college kids wall to wall in here drinking,” he said. “You don’t want a gun in here.”

On reflection, he said he might have been better off using the official state-designed sign instead of his own.

Mr. Matsko received negative feedback after posting a sarcastic sign banning concealed weapons from his restaurant. A different sign is pictured. Credit Mike Belleme for The New York Times

Mr. Matsko received negative feedback after posting a sarcastic sign banning concealed weapons from his restaurant. A different sign is pictured. Credit Mike Belleme for The New York TimesIt read, “If you are such a loser that you feel a need to carry a gun with you when you go out, I do not want your business.” The sentence followed with a derogatory term used for an obnoxious person.

The sign was up for about a month before things exploded on St. Patrick’s Day. Someone posted a photograph of the sign on Twitter. It was posted on the AR-15 Gun Owners of America Facebook page. His sleepy entry on the crowd-sourced restaurant review site Yelp jumped from a few reviews to hundreds. His stars dropped from four to one.

Reactions on Yelp and in other social media questioned Mr. Matsko’s dedication to the United States Constitution and the Second Amendment.

“ ‘We the People’ are happy to go elsewhere,” Sean Parnell, the author of “Outlaw Platoon: Heroes, Renegades, Infidels, and the Brotherhood of War in Afghanistan,” said on Twitter.

Although the state’s restaurant and lodging association took no position on the new law, some members say having to post a sign barring guns is akin to putting up a scarlet letter. Many are still deciding what to do.

One is Sean Brock, a well-regarded Southern chef with restaurants in South Carolina and Nashville.

He shot his first gun when he was 8, and sleeps beside a 9-millimeter handgun every night. But he doesn’t want guns in his Husk restaurants.

“It’s a bit strange to me that you think you need to carry a gun when you’re having a cheeseburger,” Mr. Brock said.

Still, he and his partners have not decided whether to put up signs prohibiting guns. “The pressure to make the right move is intense,” he said. “When you start to become this stage for rights, you have to be so careful. You can’t put your own beliefs up front because it’s not just a singular opinion. Your opinion will affect so many other people.”

He has already felt the pressure from advocates of stricter gun control, who came to his office the night he was opening Husk in Nashville last May.

The organization Gun-Free Dining Tennessee, which formed after that state enacted a similar piece of concealed-weapons legislation in 2009, keeps a public list of restaurants that do and do not offer gun-free dining.

Ray Friedman, a professor at Vanderbilt University who started the list, asked Mr. Brock to post a “no guns” sign or face pickets.

“I sympathize with the restaurant owners because they didn’t choose to be in the middle of this, but this is where it is playing out,” Mr. Friedman said.

The intensity of the interaction has made Mr. Brock realize how much the role of the chef has changed.

“People are really looking to you for answers and guidance and your opinion on things,” Mr. Brock said. “You have to learn how to speak like a politician when you are speaking to people. Twenty or 30 years ago you were just a guy who made eggs Benedict.”

A version of this article appears in print on April 1, 2014, on page A1 of the New York edition with the headline: Want Guns With That? Chefs Find Politics Hotter Than Kitchen. Order Reprints|Today's Paper|Subscribe